Meanwhile, toast the chilies. Heat a large skillet over medium-high heat. Lay chilies flat in
skillet and toast until fragrant and pliable and color darkens, 10 to 15 seconds a side.

Transfer chilies to a large bowl, cover with hot water and let stand 30 minutes. Wipe out
skillet.

Make the bean-chorizo mixture. While chilies soak, heat 2 tablespoons oil in the skillet over
medium-high heat. Add chorizo and cook until golden, about 5 minutes. Transfer to a
paper-towel-lined plate.

Assemble the casserole. Heat oven to 350 degrees. Spread a quarter of the chili sauce over
bottom of a 9-by-13-inch baking dish. Place a layer of 6 overlapping tortillas on top of the sauce,
followed by another layer of sauce, half the bean mixture and half the cheese. Cover with another
layer of 6 tortillas, a layer of sauce, remaining bean mixture and remaining cheese. Spoon
remaining sauce on top. Cover tightly and bake 20 minutes.

Uncover and continue baking until casserole is bubbly at edges and cheese is melted, 20 minutes
more.